Recursively convert python object graph to dictionary
I don't know what is the purpose of checking for basestring or object is? also dict will not contain any callables unless you have attributes pointing to such callables, but in that case isn't that part of object?
so instead of checking for various types and values, let todict convert the object and if it raises the exception, user the orginal value.
todict will only raise exception if obj doesn't have dict e.g.
class A(object):
def __init__(self):
self.a1 = 1
class B(object):
def __init__(self):
self.b1 = 1
self.b2 = 2
self.o1 = A()
def func1(self):
pass
def todict(obj):
data = {}
for key, value in obj.__dict__.iteritems():
try:
data[key] = todict(value)
except AttributeError:
data[key] = value
return data
b = B()
print todict(b)
it prints {'b1': 1, 'b2': 2, 'o1': {'a1': 1}} there may be some other cases to consider, but it may be a good start
special cases if a object uses slots then you will not be able to get dict e.g.
class A(object):
__slots__ = ["a1"]
def __init__(self):
self.a1 = 1
fix for the slots cases can be to use dir() instead of directly using the dict
An amalgamation of my own attempt and clues derived from Anurag Uniyal and Lennart Regebro's answers works best for me:
def todict(obj, classkey=None):
if isinstance(obj, dict):
data = {}
for (k, v) in obj.items():
data[k] = todict(v, classkey)
return data
elif hasattr(obj, "_ast"):
return todict(obj._ast())
elif hasattr(obj, "__iter__") and not isinstance(obj, str):
return [todict(v, classkey) for v in obj]
elif hasattr(obj, "__dict__"):
data = dict([(key, todict(value, classkey))
for key, value in obj.__dict__.items()
if not callable(value) and not key.startswith('_')])
if classkey is not None and hasattr(obj, "__class__"):
data[classkey] = obj.__class__.__name__
return data
else:
return obj
One line of code to convert an object to JSON recursively.
import json
def get_json(obj):
return json.loads(
json.dumps(obj, default=lambda o: getattr(o, '__dict__', str(o)))
)
obj = SomeClass()
print("Json = ", get_json(obj))
I realize that this answer is a few years too late, but I thought it might be worth sharing since it's a Python 3.3+ compatible modification to the original solution by @Shabbyrobe that has generally worked well for me:
import collections
try:
# Python 2.7+
basestring
except NameError:
# Python 3.3+
basestring = str
def todict(obj):
"""
Recursively convert a Python object graph to sequences (lists)
and mappings (dicts) of primitives (bool, int, float, string, ...)
"""
if isinstance(obj, basestring):
return obj
elif isinstance(obj, dict):
return dict((key, todict(val)) for key, val in obj.items())
elif isinstance(obj, collections.Iterable):
return [todict(val) for val in obj]
elif hasattr(obj, '__dict__'):
return todict(vars(obj))
elif hasattr(obj, '__slots__'):
return todict(dict((name, getattr(obj, name)) for name in getattr(obj, '__slots__')))
return obj
If you're not interested in callable attributes, for example, they can be stripped in the dictionary comprehension:
elif isinstance(obj, dict):
return dict((key, todict(val)) for key, val in obj.items() if not callable(val))